Mobile terminal and method for operating touch keypad thereof

ABSTRACT

A mobile terminal and method for operating a touch keypad, the mobile terminal including a touch keypad, a touch sensor for sensing a signal inputted from a key selected by a user on the touch keypad and outputting location information corresponding to the selected key based upon the sensed signal, a Control Processor (CPU) for outputting at least one or more control signals based upon the outputted location information, and a light emitting diode controller for independently driving a light emitting diode corresponding to the selected key based upon the outputted control signals.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. § 119(a), this application claims the benefit ofearlier filing date and right of priority to Korean Application No.116717/2005, filed on Dec. 2, 2005, the contents of which is herebyincorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The present invention is directed to a mobile terminal, andspecifically, to a mobile terminal and method for operating a touchkeypad capable of improving user's convenience.

DESCRIPTION OF THE RELATED ART

A mobile communications terminal is a communication device capable ofproviding a call to another party via a wireless connection anytime andanywhere under switching control of an MSC (Mobile Switching Center)while moving within a service region of a BS (Base Station). Mobilecommunications terminals having a large display device and a camerafunction for capturing videos, or moving pictures and images arerecently gaining popularity.

Mobile communications terminals are often provided with variousadditional services, such as a camera function, an MP3 (MPEG Audio Layer3) playback function, an Internet function and a SMS (Short MessagingService) function, in addition to typical communication functions inorder to provide a user with more convenience and communicationsapplications. Furthermore, the shapes (appearances) of the mobilecommunications terminals and User Interfaces (Uls) are designed based onthe various additional functions that are provided.

Portable mobile communications terminal is being manufactured smaller,lighter and slimmer for its easy carrying. Accordingly, correspondingcomponents may be replaced. Toward this end, it may be useful to providea mobile communications terminal with a touch keypad for operation.

A related art mobile communications terminal for operating an art touchkeypad is provided with an Integrated Circuit (IC) for sensing a signalat each preset portion of the touch keypad, specifically, at every pointto be touched, in order to enable performance of an operationcorresponding to a selected key based upon the signal input from the IC.However, the related art mobile communications terminal for operating atouch keypad has the IC located on the touch keypad. Accordingly, theselected key is indicated only by a user's sense, and therefore, it isdifficult for the user to recognize the selected key.

SUMMARY OF THE INVENTION

Features and advantages of the invention will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings. Anobject of the present invention is to provide a mobile terminal andmethod for operating a touch keypad capable of improving userconvenience by enabling the user to easily recognize a selected key byindependently driving only a light emitting diode corresponding to thekey selected by the user.

In one aspect of the invention, a method for operating a touch keypad ofa mobile terminal, the touch keypad having a plurality of keys and atleast one light emitting unit associated with each of the plurality ofkeys, is provided. The method includes sensing a signal input from aselected one of the plurality of keys, the signal generated by a usertouching the selected key, and illuminating the light emitting unitassociated with the selected key independent of the light emitting unitsassociated with the non-selected keys such that the user can recognizethe selected key.

It is contemplated that the method further includes generating anaudible indication of the selected key. It is further contemplated thatthe method further includes generating a vibration to indicate that oneof the plurality of keys was selected.

It is contemplated that illuminating the light emitting unit associatedwith the selected key includes turning off the light emitting unitsassociated with the non-selected keys. It is further contemplated thatilluminating the light emitting unit associated with the selected keyincludes illuminating the light emitting unit associated with theselected key such that it emits a different color than the lightemitting units associated with the non-selected keys.

It is contemplated that illuminating the light emitting unit associatedwith the selected key includes illuminating the light emitting unitassociated with the selected key such that it blinks. It is furthercontemplated that the method further includes turning off the lightemitting units associated with the non-selected keys.

It is contemplated that the method further includes illuminating thelight emitting units associated with the non-selected keys such thatthey emit a constant light. It is further contemplated that illuminatingthe light emitting unit associated with the selected key includesilluminating the light emitting units associated with the non-selectedkeys such that they emit a constant light of a first magnitude andilluminating the light emitting unit associated with the selected keysuch that it emits a constant light of a second magnitude, wherein thesecond magnitude is greater than the first magnitude. Preferably, themethod further includes generating one of an audible indication of theselected key, a vibration to indicate that one of the plurality of keyswas selected and both the audible indication and the vibration, thegenerating performed according to a preset option, the preset optionbased upon a mode, a time of day and/or a level of illuminance ofexternal light.

In another aspect of the present invention, a mobile terminal isprovided. The mobile terminal includes a transceiving unit adapted totransmit and receive signals, a touch keypad having a plurality of keysadapted to allow a user to enter information, each of the plurality ofkeys having an associated light emitting unit, and a control unitadapted to sense a signal input from a selected one of the plurality ofkeys when a user touches the selected key and to illuminate the lightemitting unit associated with the selected key independent of the lightemitting units associated with the non-selected keys such that the usercan recognize which of the plurality of keys was touched.

It is contemplated that the terminal further includes an alarm unit andwherein the control unit is further adapted to control the alarm unit togenerate an audible indication of the selected key. It is furthercontemplated that the terminal further includes a vibration unit and thecontrol unit is further adapted to control the vibration unit togenerate a vibration to indicate that one of the plurality of keys wasselected.

It is contemplated that the control unit is further adapted to turn offthe light emitting units associated with the non-selected keys and turnon the light emitting unit associated with the selected key. It isfurther contemplated that the control unit is further adapted toilluminate the light emitting unit associated with the selected key suchthat it emits a different color than the light emitting units associatedwith the non-selected keys.

It is contemplated that the control unit is further adapted toilluminate the light emitting unit associated with the selected key suchthat it blinks and illuminate the light emitting units associated withthe non-selected keys such that they emit a constant light. It isfurther contemplated that the control unit is further adapted toilluminate the light emitting units associated with the non-selectedkeys such that they emit a constant light of a first magnitude andilluminate the light emitting unit associated with the selected key suchthat it emits a constant light of a second magnitude, wherein the secondmagnitude is greater than the first magnitude.

It is contemplated that the terminal further includes an alarm unit anda vibration unit and the control unit is further adapted to detect apreset option and either control the alarm unit to generate an audibleindication of the selected key, control the vibration unit to generate avibration to indicate that one of the plurality of keys was selected andcontrol both the alarm unit to generate the audible indication and thevibration unit to generate the vibration. It is further contemplatedthat the preset option is based upon either a mode, a time of day or alevel of illuminance of external light.

It is contemplated that the mode includes either normal and manner andthe control unit is further adapted to either control the alarm unit togenerate the audible indication or control both the alarm unit togenerate the audible indication and the vibration unit to generate thevibration in normal mode and to control the vibration unit to generatethe vibration in manner mode. It is further contemplated that the timeof day includes one of morning, afternoon and night and the control unitis further adapted to control the vibration unit to generate thevibration in the morning and afternoon and either control the alarm unitto generate the audible indication or control both the alarm unit togenerate the audible indication and the vibration unit and the vibrationat night.

It is contemplated that the level of illuminance includes either abright area and a dark area and the control unit is further adapted tocontrol both the alarm unit and the vibration unit to generate theaudible indication and the vibration in a bright area and either controlthe alarm unit to generate the audible indication, control the vibrationunit the generate the vibration or control both the alarm unit and thevibration unit to generate the audible indication and the vibration in adark area. It is further contemplated that the control unit includes atouch sensor processor adapted to sense the signal input from theselected key and output location information corresponding to theselected key based upon the sensed signal, a control processor unit(CPU) adapted to output at least one control signal according to thelocation information and a light emitting unit controller adapted toindependently drive the light emitting unit associated with the selectedkey according to the at least one control signal.

It is contemplated that the terminal further includes an Inter IC Bus(IC) controller adapted to provide an IC interface between the touchsensor processor and the CPU and between the CPU and the light emittingunit controller. It is further contemplated that the terminal furtherincludes a memory adapted to store location information corresponding toeach of the plurality of keys.

It is contemplated that the CPU is further adapted to output a controlsignal for controlling the light emitting unit associated with theselected key based upon the key location information from the touchsensor processor and the location information stored in the memory. Itis further contemplated that the touch keypad includes capacitorsarranged in an arbitrary form.

It is contemplated that the touch sensor processor is further adapted tosense a signal input from the selected key according to changes incapacitance values. It is further contemplated that the touch keypadfurther includes a first unit providing the light emitting unitsassociated with the plurality of keys, a second unit providing guidingportions adapted to guide light from each light emitting unit to theassociated one of the plurality of keys and a touch keypad panelproviding the plurality of keys. Preferably, the touch keypad includes afirst unit providing the light emitting units associated with theplurality of keys, a second unit providing guiding portions adapted toguide light from each light emitting unit to the associated one of theplurality of keys and additional light emitting units adapted to providebacklighting for the plurality of keys and a touch keypad panelproviding the plurality of keys.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. It is to beunderstood that both the foregoing general description and the followingdetailed description of the present invention are exemplary andexplanatory and are intended to provide further explanation of theinvention as claimed.

These and other embodiments will also become readily apparent to thoseskilled in the art from the following detailed description of theembodiments having reference to the attached figures, the invention notbeing limited to any particular embodiments disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention. Features, elements, and aspects of the invention that arereferenced by the same numerals in different figures represent the same,equivalent, or similar features, elements, or aspects in accordance withone or more embodiments.

FIG. 1 is a block diagram illustrating a structure of a mobile terminalfor operating a touch keypad according to the present invention.

FIG. 2 illustrates a structure of a touch keypad of a mobile terminalaccording to the present invention.

FIG. 3 is a flowchart illustrating a method for operating a touch keypadof a mobile terminal according to the present invention.

FIG. 4 illustrates a principle for sensing location information of atouch sensor processor according to the present invention.

FIGS. 5A through 5D illustrates a principle for using a touch keypad ofa mobile terminal according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With respect to the attached drawings, explanation will be given ofpreferred embodiments of a mobile terminal and method for operating atouch keypad capable of improving convenience of a user by which theuser can easily recognize a selected key by independently operating onlya light emitting diode corresponding to a key selected by the user onthe touch keypad. The mobile terminal to which the present invention maybe applied is not limited to mobile phones but rather includes PersonalDigital Assistants (PDAs), notebooks and Portable Multimedia Players(PMPs), all of which use a keypad.

FIG. 1 is a block diagram illustrating a structure of a mobile terminal100 for operating a touch keypad according to the present invention. Asillustrated in FIG. 1, the mobile terminal 100 may include a transceiver110, a touch keypad 150, a touch sensor processor 151 for sensing asignal input from a key selected by a user on the touch keypad andoutputting location information corresponding to the selected key basedupon the sensed signal, a Control Processing Unit (CPU) 130 foroutputting one or more control signals based upon the outputted locationinformation, a light emitting diode (LED) controller 153 forindependently driving the light emitting diode corresponding to theselected key based upon a first control signal, an alarm unit 120 foroutputting an alarm sound corresponding to the selected key based upon asecond control signal, a vibration unit 121 for generating a vibrationcorresponding to the selected key based upon a third control signal, anInter IC Bus (I2C) controller 152 for providing an I2C interface betweenthe touch sensor processor and the CPU and between the CPU and the lightemitting diode controller and a memory 140 for storing an arbitrary keyon the touch keypad and location information corresponding to thearbitrary key. The light emitting diode controller 153 turns off thelight emitting diodes corresponding to non-selected keys, specificallyall keys except for the selected key, such that the user can easilyrecognize the selected key.

The touch keypad 150 may be implemented in various shapes on variouspositions according to a type of mobile terminal, for example, a slidetype, a folder type, or a swing type. Explanation of the presentinvention will be with respect to structure of the touch keypad of themobile terminal.

FIG. 2 illustrates a structure of a touch keypad of a mobile terminalaccording to the present invention. As illustrated in FIG. 2, the touchkeypad 150 according to the present invention may include a firstPrinted Circuit Board (PCB) 154 provided with a plurality of lightemitting diodes, a second PCB 155 provided above the first PCB such thateach of the light emitting diodes corresponds to an arbitrary key, and atouch keypad panel 156 provided above the second PCB and having a touchkeypad.

LEDs for providing backlight for the keys of the touch keypad 150 and aguide portion for providing light from each of the LEDs to acorresponding key of the keypad may be provided on the second PCB 155.The second PCB 155 may be an EL (OLED) sheet.

The second PCB 155 may have a plurality of grooves into which the lightemitting diodes are inserted. Each groove penetrates upper and lowerportions of the second PCB 156 to allow light emitting diodes to beinserted. The touch keypad 150 may be implemented in various shapes.

FIG. 3 illustrates a flowchart of a method for operating a touch keypadof a mobile terminal according to the present invention. As illustratedin FIG. 3, the method may include sensing a signal inputted from a keyselected by a user on a touch keypad (S310), outputting locationinformation corresponding to the selected key based upon the sensedsignal (S320), outputting one or more control signals based upon thelocation information (S330), independently driving a light emittingdiode corresponding to the selected key according to a first controlsignal (S340), generating an alarm sound corresponding to the selectedkey according to a second control signal (S350), and generating avibration corresponding to the selected key based upon a third controlsignal (S360).

The touch keypad 150 is provided with not only light emitting diodes forperforming a backlight function but also light emitting diodes forfacilitating recognition of a selected key, whereby all of the lightemitting diodes may be driven or turned on, and also a light emittingdiode corresponding to the selected key can be independently driven. Thelight emitting diodes preferably are three-color LEDs. Furthermore, themobile communications terminal 100 may independently drive the lightemitting diode corresponding to the selected key and simultaneouslygenerate an alarm sound or vibration corresponding to the selected key.

The touch sensor processor 151 senses a signal input from a key selectedby a user on the touch keypad (S310) and outputs location informationcorresponding to the selected key based upon the sensed signal (S320).The touch sensor processor 151 calculates the location information basedupon the sensed signal and outputs the calculated information to the CPU130 via the I2C controller 152. The CPU 130 can then perform anoperation according to the selected key on the touch keypad 150.Preferably, the touch sensor processor 151 is implemented as a System onChip (SoC) device, which can replace tens of mechanical switches andregulators.

FIG. 4 illustrates a principle for sensing location information of thetouch sensor processor 151 according to the present invention. Asillustrated in FIG. 4, in the touch sensor processor 151, when anarbitrary portion of the touch keypad is selected or touched, forexample, with a user's finger or a pen, capacitance values are generatedby the finger or pen in addition to a capacitance value generatedbetween touch sensors positioned at the selected location. As a result,a certain number of sawtooth waves are generated for a certain timeaccording to a clock by the capacitance value generated between thetouch sensors at the selected location. The capacitance values generatedfrom the finger or pen increase a time constant of the sawtooth waves,which results in a decrease of the number of sawtooth waves generatedaccording to the clock for the certain time. Accordingly, the touchsensor processor 151 can sense the location of the selected key.

The CPU 130 outputs one or more control signals for controlling anoutput of one or more output units, for example, the light emittingdiodes, the alarm unit 120, and the vibration unit 121 according tolocation information (S330). That is, the CPU 130 can output a controlsignal to the light emitting diode controller 153 via the I2C controller152 for controlling the light emitting diode corresponding to theselected key, the control signal based on the location information andinformation previously stored in the memory 140.

The I2C controller 152 facilitates data communication between the touchsensor processor 151 and the CPU 130 or between the CPU and the lightemitting diode controller 153 via an I2C interface. The I2C interface,which is a bus for communication between the CPU 130 and various I/Odevices, generally uses a Serial Clock Line (SCL) for transmitting aclock and a Serial Data Line (SDA) for transmitting data. In addition,the I2C controller 152 may provide an Interrupt ReQuest (IRQ) line forcontrolling a direction of the data transmission via the SDA.

Accordingly, the light emitting diode controller 153 independentlydrives the light emitting diode corresponding to the selected key basedupon a first control signal (S340). The alarm unit 120 outputs an alarmsound corresponding to the selected key based upon a second controlsignal (S350). The vibration unit 121 generates a vibrationcorresponding to the selected key based upon a third control signal(S360).

The light emitting diode controller 153 may drive the light emittingdiode corresponding to the selected key such that the selected keyblinks. The light emitting diode controller 153 may drive the lightemitting diodes corresponding to the other keys such that they emit aconstant light.

When independently driving the light emitting diode corresponding to theselected key, the light emitting diode controller 153 can turn off thelight emitting diodes that provide the touch keypad 150 with a backlightfunction or control the LEDs to emit light of a different color than thecolor emitted by the light emitting diode corresponding to the selectedkey. That is, the light emitting diode controller 153 can control thelight emitting diode corresponding to the selected key and the lightemitting diodes providing the backlight function in order to allow auser to easily recognize the selected key.

The mobile communications terminal 100 according to the presentinvention can provide light-emission, an alarm sound and/or vibrationfor facilitating a user's recognition of a selected key in several waysaccording to various environments. Several examples are provided.

First, whether an alarm sound or a vibration is generated may bedetermined based upon modes. For a normal mode, light-emission and analarm sound or light-emission, an alarm sound and vibration may begenerated, whereas for a manner mode, light-emission and vibration maybe generated.

Second, whether an alarm signal or a vibration is generated may bedetermined based upon time of day. In the morning or in the afternoon,most time is spent in offices or schools, and accordingly light-emissionand vibration may be generated, whereas at night, most time is spent athome and, accordingly, light-emission and an alarm sound or,light-emission, an alarm sound and vibration may be generated.

Third, whether an alarm signal or a vibration is generated may bedetermined based upon luminance. In a bright area, it is difficult torecognize light-emission and, accordingly an alarm sound or vibrationmay be generated, whereas in a dark area, light-emission and an alarmsound or light-emission and vibration or light-emission, an alarm soundand vibration may be generated.

FIGS. 5A through 5D are views illustrating a principle for employing atouch keypad 150 of a mobile terminal 100 according to the presentinvention. As illustrated in FIG. 5A, the touch keypad 150 can providethe backlight function. When the mobile terminal 100 is closed all thelight emitting diodes may be turned off, and when the mobile terminal itis opened, all the light emitting diodes may be driven, or turned on.

As illustrated in FIGS. 5B and 5C, when a user selects an arbitrary key,such as a menu key (-) or a numeral key (7-key) to search for a menu orplace a call in an active state of the mobile terminal 100, the touchkeypad 150 can independently drive the light emitting diode related tothe selected key in order to facilitate a user's recognition of theselected key and can turn off all light emitting diodes corresponding toother keys.

In a dimming mode, the touch keypad 150 can turn off all the lightemitting diodes, and when a user selects an arbitrary key, the touchkeypad can independently drive the light emitting diode corresponding tothe selected key and turn off all the light emitting diodescorresponding to other keys. Thereafter, in addition to independentlydriving the light emitting diode corresponding to the selected key, anamount of the light emitted by a light emitting diode corresponding tothe selected key is increased and an amount of the light emitted bylight emitting diodes corresponding to the other keys is decreased tothereby facilitate a user's recognition of the selected key.

As illustrated in FIG. 5D, even when the mobile terminal 100 is closed,the touch keypad 150 can be activated. Specifically all the lightemitting diodes can be driven by a preset function key in order toperform functions such as phone book search or text messageconfirmation.

The touch keypad 150 can independently drive only the light emittingdiode corresponding to the selected key. Also, the light emitting diodescorresponding to respective keys on the touch keypad 150 may beimplemented such that each light emitting diode can emit light withdifferent color by using LEDs which can render various colors. Forexample, when the light emitting diode corresponding to the key selectedby the user is driven to emit light, the light emitting diodescorresponding to non-selected keys can be turned off or can be driven toemit light with a corresponding color that is different from the colorof the light emitted from the light emitting diode corresponding to theselected key.

The touch keypad 150 can be implemented such that the light emittingdiodes can emit light with various colors other than the three basiccolors by a combination of different colors of the LED (i.e., thethree-color LED) that can render various colors.

As described in the mobile terminal and method for operating a touchkeypad according to the present invention can independently drive thelight emitting diode corresponding to the key selected by the user onthe touch keypad in order to facilitate a user's recognition of theselected key. As a result, user convenience is effectively improved.

As the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be construed broadly within itsspirit and scope as defined in the appended claims. Therefore, allchanges and modifications that fall within the metes and bounds of theclaims, or equivalents of such metes and bounds are therefore intendedto be embraced by the appended claims.

The foregoing embodiments and advantages are merely exemplary and arenot to be construed as limiting the present invention. The presentteaching can be readily applied to other types of apparatuses. Thedescription of the present invention is intended to be illustrative, andnot to limit the scope of the claims. Many alternatives, modifications,and variations will be apparent to those skilled in the art. In theclaims, means-plus-function clauses are intended to cover the structuredescribed herein as performing the recited function and not onlystructural equivalents but also equivalent structures.

1. A method for operating a touch keypad of a mobile terminal, the touchkeypad having a plurality of keys and at least one light emitting unitassociated with each of the plurality of keys, the method comprising:sensing a signal input from a selected one of the plurality of keys, thesignal generated by a user touching the selected key; and illuminatingthe light emitting unit associated with the selected key independent ofthe light emitting units associated with the non-selected keys such thatthe user can recognize the selected key.
 2. The method of claim 1,further comprising generating an audible indication of the selected key.3. The method of claim 1, further comprising generating a vibration toindicate that one of the plurality of keys was selected.
 4. The methodof claim 1, wherein illuminating the light emitting unit associated withthe selected key comprises turning off the light emitting unitsassociated with the non-selected keys.
 5. The method of claim 1, whereinilluminating the light emitting unit associated with the selected keycomprises illuminating the light emitting unit associated with theselected key such that it emits a different color than the lightemitting units associated with the non-selected keys.
 6. The method ofclaim 1, wherein illuminating the light emitting unit associated withthe selected key comprises illuminating the light emitting unitassociated with the selected key such that it blinks.
 7. The method ofclaim 6, further comprising turning off the light emitting unitsassociated with the non-selected keys.
 8. The method of claim 6 furthercomprising illuminating the light emitting units associated with thenon-selected keys such that they emit a constant light.
 9. The method ofclaim 1, wherein illuminating the light emitting unit associated withthe selected key comprises: illuminating the light emitting unitsassociated with the non-selected keys such that they emit a constantlight of a first magnitude; and illuminating the light emitting unitassociated with the selected key such that it emits a constant light ofa second magnitude, wherein the second magnitude is greater than thefirst magnitude,
 10. The method of claim 1, further comprisinggenerating one of an audible indication of the selected key, a vibrationto indicate that one of the plurality of keys was selected and both theaudible indication and the vibration, the generating performed accordingto a preset option, the preset option based upon one of a mode, a timeof day and a level of illuminance of external light.
 11. A mobileterminal, comprising: a transceiving unit adapted to transmit andreceive signals; a touch keypad having a plurality of keys adapted toallow a user to enter information, each of the plurality of keys havingan associated light emitting unit; and a control unit adapted to sense asignal input from a selected one of the plurality of keys when a usertouches the selected key and to illuminate the light emitting unitassociated with the selected key independent of the light emitting unitsassociated with the non-selected keys such that the user can recognizewhich of the plurality of keys was touched.
 12. The terminal of claim11, further comprising an alarm unit and wherein the control unit isfurther adapted to control the alarm unit to generate an audibleindication of the selected key.
 13. The terminal of claim 12, furthercomprising a vibration unit and wherein the control unit is furtheradapted to control the vibration unit to generate a vibration toindicate that one of the plurality of keys was selected.
 14. Theterminal of claim 11, wherein the control unit is further adapted toturn off the light emitting units associated with the non-selected keysand turn on the light emitting unit associated with the selected key.15. The terminal of claim 11, wherein the control unit is furtheradapted to illuminate the light emitting unit associated with theselected key such that it emits a different color than the lightemitting units associated with the non-selected keys.
 16. The terminalof claim 11, wherein the control unit is further adapted to: illuminatethe light emitting unit associated with the selected key such that itblinks; and illuminate the light emitting units associated with thenon-selected keys such that they emit a constant light.
 17. The terminalof claim 11, wherein the control unit is further adapted to: illuminatethe light emitting units associated with the non-selected keys such thatthey emit a constant light of a first magnitude; and illuminate thelight emitting unit associated with the selected key such that it emitsa constant light of a second magnitude, wherein the second magnitude isgreater than the first magnitude.
 18. The terminal of claim 11 furthercomprising an alarm unit and a vibration unit and wherein the controlunit is further adapted to detect a preset option and one of control thealarm unit to generate an audible indication of the selected key,control the vibration unit to generate a vibration to indicate that oneof the plurality of keys was selected and control both the alarm unit togenerate the audible indication and the vibration unit to generate thevibration.
 19. The terminal of claim 18, wherein the preset option isbased upon one of a mode, a time of day and a level of illuminance ofexternal light.
 20. The terminal of claim 19, wherein the mode comprisesone of normal and manner and the control unit is further adapted to oneof control the alarm unit to generate the audible indication and controlboth the alarm unit to generate the audible indication and the vibrationunit to generate the vibration in normal mode and to control thevibration unit to generate the vibration in manner mode.
 21. Theterminal of claim 19, wherein the time of day comprises one of morning,afternoon and night and the control unit is further adapted to controlthe vibration unit to generate the vibration in the morning andafternoon and one of control the alarm unit to generate the audibleindication and control both the alarm unit to generate the audibleindication and the vibration unit and the vibration at night.
 22. Theterminal of claim 19, wherein the level of illuminance comprises one ofa bright area and a dark area and the control unit is further adapted tocontrol both the alarm unit and the vibration unit to generate theaudible indication and the vibration in a bright area and one of controlthe alarm unit to generate the audible indication, control the vibrationunit the generate the vibration and control both the alarm unit and thevibration unit to generate the audible indication and the vibration in adark area.
 23. The terminal of claim 11, wherein the control unitcomprises: a touch sensor processor adapted to sense the signal inputfrom the selected key and output location information corresponding tothe selected key based upon the sensed signal; a control processor unit(CPU) adapted to output at least one control signal according to thelocation information; and a light emitting unit controller adapted toindependently drive the light emitting unit associated with the selectedkey according to the at least one control signal.
 24. The terminal ofclaim 23, further comprising an Inter IC Bus (I2C) controller adapted toprovide an I2C interface between the touch sensor processor and the CPUand between the CPU and the light emitting unit controller.
 25. Theterminal of claim 23, further comprising a memory adapted to storelocation information corresponding to each of the plurality of keys. 26.The terminal of claim 25, wherein the CPU is further adapted to output acontrol signal for controlling the light emitting unit associated withthe selected key based upon the key location information from the touchsensor processor and the location information stored in the memory. 27.The terminal of claim 11, wherein the touch keypad comprises capacitorsarranged in an arbitrary form.
 28. The terminal of claim 27, wherein thetouch sensor processor is further adapted to sense a signal input fromthe selected key according to changes in capacitance values.
 29. Theterminal of claim 11, wherein the touch keypad further comprises: afirst unit providing the light emitting units associated with theplurality of keys; a second unit providing guiding portions adapted toguide light from each light emitting unit to the associated one of theplurality of keys; and a touch keypad panel providing the plurality ofkeys.
 30. The terminal of claim 11, wherein the touch keypad comprises:a first unit providing the light emitting units associated with theplurality of keys; a second unit providing guiding portions adapted toguide light from each light emitting unit to the associated one of theplurality of keys and additional light emitting units adapted to providebacklighting for the plurality of keys; and a touch keypad panelproviding the plurality of keys.